1. Field of the Invention
The present invention relates to a wire saw and a method of slicing an ingot by the wire saw, and more particularly to a wire saw and a method of slicing the ingot by the wire saw, for slicing the single crystal material such as silicon into a large number of wafers.
2. Description of the Related Art
When a wire saw slices an ingot such as silicon, the ingot needs to be inclined at a predetermined angle with regard to a wire row so that a sliced surface can be a predetermined crystal surface.
In the conventional wire saw, a tilting apparatus, which is integrated with a work feed table, aligns a crystal orientation for the ingot. The tilting apparatus supports the single crystal material so that the ingot can rock in vertical and horizontal directions with regard to the wire row. The user aligns the crystal orientation manually based on the previously-obtained data relating to the crystal orientation.
However, the tilting in the main body of the wire saw apparatus is restricted in space, so the operation is extremely difficult. Moreover, the operation requires much time, and the slicing cannot be performed efficiently.
Furthermore, if the ingot inclines vertically with regard to the wire row in order to be sliced, one end of the ingot is sliced first as shown in FIG. 14. So, there is a disadvantage in that the heat is concentrated at one side of grooved rollers which form the wire row; therefore, the slicing accuracy is lowered.